The anteroventral wall of the third ventricle and the angiotensinergic component of need-induced sodium intake in the rat.

Because the anteroventral wall of the third ventricle (AV3V) has been implicated in the control of sodium intake it was studied in rats with damage of the AV3V region in the sodium-replete and sodium-deplete states, and when they were treated with either pulse intracerebroventricular (pICV) injection of renin to activate brain angiotensin or daily subcutaneous injections of deoxycorticosterone (DOCA). The response of rats with AV3V damage to sodium depletion was retarded and the excess sodium intake that is induced by pICV renin was absent, but their daily need-free sodium intake and the sodium intake that is induced by DOCA were essentially normal. The results suggest that the AV3V is responsible for the angiotensinergic, but not the aldosteronergic, component of the ANG II/ALDO synergy that controls need-induced sodium appetite in the rat. The integrity of the AV3V is not necessary for daily need-free sodium intake or for its enhancement by sodium depletions, suggesting that ANG II is probably not important for these phenomena. But ANG II action within the AV3V might be important for the rapid burst of sodium intake that immediately follows a period of depletion.